ignoring vim swap files
makes unbind match bind api signature call

The old way wasn't consistent, bind passed the app hostname and unit
host in the request body, while unbind passed only the unit host
in the querystring. Now both pass their parameters in the request body.

Change in the bind.Binder interface were needed, so we could receive the
app when unbinding an unit.

Relates to #794
updates service api and build docs to match current implementation of bind/unbind

also fixes some typos: s/service-name/service-instance-name on
bind/unbind.
Merge branch 'master' of github.com:tsuru/tsuru into bind_unbind_mismatch_fix#794
removes ignore of vim's swap files
removes print from test function
Merge pull request #951 from tsuru/bind_unbind_mismatch_fix#794

Bind unbind mismatch fix#794